We're thinking about switching the default backend on the mon from leveldb to rocksdb. Rocksdb is better maintained, has a stronger feature set, is generally faster, and is linked statically, which means we won't be vulnerable to buggy distro packages. There is one blocker, though. Some distro leveldbs name the sst files with the .ldb suffix. (Some don't; very annoying.) There is a unit test in rocksdb that tries to verify that ldb is silently renamed to sst, and it passes, but the test is incomplete: the test failes to verify that ldb/sst files can actually be read, and it turns out only the 'check' path (not the normal open and read it path) handles ldb properly. Anyway, once that works, rocksdb will magically upgrade from leveldb to rocksdb. Note that once that happens you can't switch from rocksdb back to leveldb without recreating the mon. Alternatively, we could not worry about upgrading existing leveldb instances and just make newly created mons default to rocksdb. 1) Thoughts on moving to rocksdb in general? 2) Importance of leveldb->rocksdb conversion? 3) Anyone want to fix the ldb handling in rocksdb? Thanks! sage -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
